snow load on trellis

huangyhg

snow load on trellis
at what point is a trellis roof considered to be covered enough to carry a snow load? is this covered in any of the codes?  thanks for the info!
and what if it gets covered with plants and birds build nests in it.  that is what happened to me.  if you want to get real conservative - just assume it's a flat roof with very good drainage.
i had a trellis that was so covered with vines that they literally pulled it down an inch or two per year.  the columns had finally started to decay.  so when it got down to about 6' tall - i took it down!!